Thursday, December 24, 2009

I used to hate U3...

U3 is that annoying software that comes pre-installed on your Sandisk thumb drives.  It mounts a virtual CD on your PC when you plug it in and auto-runs a piece of crappy software when all you want is to drag and drop files onto your thumb drive.  I hate that.

But wait - I USED to hate U3. U3 was a closed, windows-only, back-door, auto-run, BS that Sandisk forced me to borrow a Microsoft PC to rip out of my thumb-drive...

I was so wrong. 

I discovered I could hack it. And that CD partition on the U3 drive... looks like a real CD to the computer... and it's bootable! The CD acts like a separate device on an USB hub!

I now have a bootable, 8GB Sandisk Cruzer thumbdrive with all the useful boot CD's I use - all selectable from a little menu. I haven't perfected it yet, but I have half a dozen of them already on there. I want to work on it some more and then post it so all zero of you can easily do this too. :-p

For now, here are some links to the bits and pieces I used (both are cross platform Windows-Linux-Mac-whatever that has mkisofs):
u3-tool - Allows customization of the u3 partition.
UBCD - Has a bunch of boot images pre-installed and easy directions for customizing.

So far, I left all the stuff that came on the UBCD with a few tweaks:
  • I upgraded to the latest memtest86+, and DBAN.
  • I added SpinRite. (The only piece of software I've bought in a decade.)
  • I added the following Live CD's:
  1. TinyCore v2.7 - 10MB, runs almost everything useful, boots into ram 5-10 seconds. Enough said.
  2. Puppy Linux v4.3.1 - A little bigger, also runs in RAM, less customization needed.
  3. Slax 6.3.1 - Most polished Live CD I ever used. Only 200 MB base image. Online customization. Check it out.
  4. BackTrack 4 - 1.3GB of evil hacker tools
    "computer security tools". Mwahahaha.

Really this was mostly a no-brainer with just the two links above. I had to do some hacking editing of the isolinux configs (which requires a bit more than monkey skills) to get things just right, but it was really pretty easy.

The coolest thing is that the live CD's are read only and behave just like a giant CD. The thumb-drive still shows up as a thumb-drive too. It acts like a separate device to the PC. (An U3 thumb-drive acts like a hub with two devices plugged into it.) This has some really cool implications.

Now I say... U3 ROCKS!


  1. Cool! I tried U3 several times on Windows and it nearly always crashed, so I too was looking for a Sandisk Cruzer sans U3. The data partition always worked just great. I'll have to try this!

  2. I'm looking forward to the update on the subject! I just recieved an 8GB Cruzer and I'm wondering what to do with it. I checked out some of the source stuff you posted, it all seems usefull. I'm lost about the bootable-nes of the drive?

    Good luck and speedy success!


  3. You don't need U3 to have a bootable thumb drive.

  4. No need to boot a w1nbl0ws VM for crap removal = Infinite Win.

    ro cdrom device with iso of my choosing = Infinite Win.

    Cheers Muchly ;)

  5. I realize that you don't need U3 to have a bootable CDROM. But, try finding the CDROM port on a netbook.

    I know about unetbootin. It's an awesome tool. However, LiveCD's are distributed as CD's and it's a crapshoot with other methods (including unetbootin) whether they're going to boot.

    This works all the time as long as the CD itself works. And it's treated as read-only. And it's treated differently by the computer as far as auto-run. And I think it's cool.

  6. (I fat fingered my last post. I meant to say I realize that you don't need U3 to make a bootable thumb drive.)

  7. Hmmm. Where do the .iso images go?


  8. I was just about to destroy the U3 partition on my flash-drive (like I normally do) when I came across this post. I like the idea!

    I found the tutorial you posted (your next post) but am wondering how you added additional live cds to your drive. Presumably you combined several iso files into one and then edited the bootloader config, but an overview/tutorial of that process would be nice :)


  9. I caught your blog via TomsHardware, thanks for this, I have an EEEPC and this will come insanely handy. About to go get a Sandisk flash drive that should have this software on it.

  10. What do I do about the contents on the flash drive like the launchu3.exe can I delete that?

  11. Wow, thanks for the tip on this one! I purchased a pack of 3 Sandisk 4GB sticks and was totally pissed off to find the irremovable Windows software on it.

    Thanks to your information posted here, I'm loading them up with other Linux distros and also good old Starcraft for my netbook.

    So cool.

  12. Wow, this is a great idea! I bought a 16G SanDisk Cruzer several months back, and was rather forced into using the U3 system that came on it. I'd much prefer to be able to go back to plain old portable apps! I didn't know there was anything I could do about the read-only partition, but now I'm getting all sorts of ideas to try out for getting some use out of that 'wasted' space! Thank you!

  13. Combine this with - a script that lets you combine multiple live CDs in one iso - and you get something really powerful.

  14. Thanks for your post pointing to the u3_tool project! I am now free of the pesky U3 software. woot!